Method of making conical containers



Dec. 6, 1938. w. E AMBERG METHOD OF MAKING CONICAL CONTAINERS 2 Sheets-Sheet 1 Filed April 2'7, 1938' v INVENTOR.

WQZZErEQ/Yweg ATTORNEY.

W. E. AMBERG Dec. 6, 1938.

METHOD OF MAKING CONICAL CONTAINERS Filed April 27, 1938 2 Sheets-Sheet 2 1N VEN TOR. WaZzeridme/ g,

ATTORNEY.

Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE METHOD OF MAKING CONICAL CONTAINERS Application April 27, 1938, Serial No. 204,671

6 Claims.

This invention relates to conical vessels, more particularly paper cups, and has for an important object thereof the provision of a new and improved method of making cone-shaped paper cups for use in dispensing water, soda and other liquids. It especially relates to a method of cutting the sheet material from which the cup is made and to a method of forming said material into a cup.

This application contains claims directed to subject matter which was disclosed but could not be claimed in my Patent No. 2,056,893, granted October 6, 1936.

A cup of a type commonly used today is disclosed in Reissue Patent No. 15,381, granted June 13,- 1922, upon application of one D. F. Curtin. As therein shown, the blank from which the cup is formed is of approximately triangular form, having an extension located at the junction of two converging edges. In the manufacture of cups from blanks of this type and in the manufacture of paper cups generally today it is customary to die stamp the blanks for a large sheet of suitable paper. In so doing the paper is stretched across a flat surface and the dies, which are arranged to cut the maximum number of blanks from the paper, descend and perform the cutting operation. Thereafter the blanks are stacked, magazined and subsequently are fed singly to a cup-folding mechanism. In forming blanks of such configuration a great deal of paper is wasted despite the care which may be exercised in arranging the dies.

It has also been heretofore proposed to form cup blanks from a roll of paper'by stamping them or cutting them from the roll, one by one, as-the paper is unwound. Here again, however, owing to the shape or configuration of the blank, a considerable amount of the paper in the roll is wasted. Such paper is scrapped and forms no part of the finished cup.

With the foregoing desiderata in view, an im portant feature of the present invention resides in the provision of a method of cutting a sheet material to produce a blank suitable for making conical vessels from a roll of paper, without any appreciable loss or waste thereof, and a method of forming said material into a cup.

In accordance with the practice of the present invention, a roll of paper, the width of which corresponds to the width of the cup blank, is cut transversally in a manner hereinafter to, be described to form a series of blanks without waste,

Another important feature of the invention resides in the provision of an improved cup formed from blanks of the character herein described. This cup is distinguished by the fact that it has a double thickness at its top portion where strength is desired, and a single thickness, at its bottom or apex portion where strength is not essential. The provision of a cup of this type permits the use of lighter stock and inasmuch as there is no waste resulting, a stronger cup is obtained. In other words, although the paper stock may be lighter, the entire stock goes into the cup, none of it being scrapped, with the result that a stronger, more rigid container is obtained.

Other objects and features of the invention will become apparent from a reading of the following speciflcation in the light of the accompanying drawings, in which Figure .1 is a top plan view of a cup making machine and process capable of practicing the improved method;

Figure 2 is a view in side elevation of the apparatus shown in Figure 1;

Figure 3 is a detailed view of the cones illustrated in Figures 1 and 2;

Figure 4 shows a conical cup in the process of being formed;

Figure 5 is a completed cup shown in perspective; and

Figure 6 is a top plan view looking downwardly into the cup shown in Figure 5. v

As illustrated in Figures 1 and 2, a strip of paper It), the width of which corresponds to the width of the cup blank to be formed therefrom, is fed from a roll of paper 8. A vertically reciprocal knife [4 is provided for the purpose of cutting a blank Hi from the end of the continuous strip of paper. -As illustrated, the shape of the cut is an arcuate one with the center of the are I coinciding with the longitudinal axis of the strip. All of the arcs have equal radii. It will be noted from the preferredembodiment illustrated in the drawings that the radius of curvature of each arc has its center at the intersection of the central vertical axis with each succeeding arc. As the strip is fed past the knife successive blanks are formed having their upper and lower edges correspondingly curved and their side edges parallel.

Blanks cut from the strip by means of the knife 14 cooperating with a cutting edge 2|] are magazined in stack 22 and .are fed singly therefrom to a plurality of cup forming instrumentalities 24 and 26 by means of a first feed roll 28 and a pair of cooperating feed and gluing rolls 30, 32.

In operation, the initialfeed roll 28 rotates and upon each rotation of the roll the lowermost blank in the magazine is fed forward to the rolls 32 and 30, which rotate in opposite directions. The lowermost roll 32 has cooperative engagement with a roll 34 mounted in a glue box 36 in such a manner that an adhesive 38 (Figure 1) is applied tothe blank as it is being fed from the magazine to the forming instrumentalities 24 and 26.

Turning to these latter members, as shown in Figure 3 they comprise a plurality of cones mounted to rotate upon shafts 40, 42, the latter of which is provided with a central aperture 44 commu nicating with a passageway 46 which extends centrally of the lower cone 26. The purpose of the passageway is two-fold. In the first place, it serves as a pick-up device at the beginning of a cup forming operation, and in the second place, as a discharge device at the completion of an operation. Thus, in the beginning of an operation suction is applied through a passageway 48 which, by means of an annular groove 50, is in constant communication with the conduit 46, and this suction is communicated through a branch passageway to an opening 52 located in the exterior of the cone 26 near the base thereof. In the position shown in Figure 1 this opening overlies the forward pointed extremity of the cup blank and the suction exerted causes the latter to adhere to the cone at the commencement of the forming operation and holds it as the forming operation takes place. After the blank has been wound around the lower cone with the upper cone serving as a forming instrumentality, the two cones are separated in the manner illustrated in Figure 1 to permit the formed cup to be discharged into a stack 52, shown in Figures 1 and 2.

Separation of the cones is permitted in a novel fashion. Heretofore to effect this separation it has been customary to separate bodily the cones generally by lifting the upper one to remove it completely out of engagement with the lower. This has its drawbacks owing to the problems involved and has been eliminated in accordance with the present invention in which the lowermost cone can be swung out of alignment with the upper cone by means of movement imparted to an arm 60 extending outwardly from the cone supporting casing 62. Thus, by swinging the arm 60 in the manner illustrated in Figure 1, the lower cone is swung laterally out of alignment and engagement with the upper cone into a discharge position, whereupon compressed air instead of suction is supplied through the passageway 48, causing the formed cup to be blown from the cone into the stack 52. During this separating operation there is no disengagement of gears or other driving instrumentalities because, as illustrated in Figure 3, the driven gear 64 merely rotates about the driving gear 66 which'is mounted upon the upper extremity of 'a driving shaft 68. Thus, by moving the arm 60 it is possible to cause the lower cone 26 to move laterally into or out of alignment with the upper cone, easily, expediently and without disengaging any driving or driven parts.

Turning now to Figures 4, and 6 and the cup blank and cup illustrated therein, it will be appreciated that when thecenter of radius of curvature of the convex side. is in the central portion of the concave side, a cup may be formed from the resultant blank which is perfectly symmetrical in every respect. If the center of the radius of curvature of the convex side is above the concave side, that is, within the blank, a cone made by winding the blank around the central portion of the concave side will have a pointed apex, but the base portion, that is, the top of the cup, will be truncated. If the center of radius of curvature of the convex side of the blank is below the concave side, that is, falls entirely outside of the blank, the resultant cone made by symmetrically winding the blank around the central portion of the concave side will not have a pointed apex, but rather the apex will be truncated. It will be noted further that in making the blank of the present invention the convex are, if projected, will intersect the concave arc. In fact, a twosided blank may be made by projecting the convex side until it meets the concave side. If the center of radius of curvature of the convex side is on the center of the concave side, this blank will form a perfectly symmetrical cup, just as the blank shown in the drawings. However, in making such a blank, it is not possible to do so without some waste. The centers of the arcs do not have to be on the central vertical axis but should preferably substantially coincide with each succeeding arc and each single arc should preferably terminate in the edge of the strip.. A three-sided blank may be made by having the line joining the centers of curvature of the arcuate sides coincide w th the edge of the strip, in which case the blank will have one straight side and two intersecting arcuate sides. It should be observed that the arcuate sides always have their centers on the, same straight line joining the centers and are spaced apart at the straight line joining the centers at least a distance equal to the radii of curvature. Further, it should be noted that the convex side of the blank formed when a continuous strip of paper is severed is adapted to form the mouth of the receptacle.

As illustrated in Figure 4, the side edgesare I indicated by the reference numerals 14, 16, the bottom edge, so termed because it forms the bottom 'of the cup, by reference numeral 18, and the upper edge, which forms the top of the cup, by the reference numeral 80. The upper and lower sides of eacli blank may also be termed convex and concave, respectively. The cup blank is symmetrical with respect to the longitudinal axis of the strip of paper I 0, which axis may be termed the vertical axis of the severed blank, as indicated by the line A-A in Figure 4, which is to say that for every point on the blank to the left of the axis A-A of Figure 4 there is a corresponding point on the portion of the blank lying to the right of the line.

As may be clearly seen from as much of the description as has already been given, the blanks are successively formed, with the upper edge of one blank corresponding to the lower edge of the blank in the rear, in such a manner that no waste results. Every particle of the paper strip shown in Figure 1 may be employed in forming the cup of Figures 4, 5 and 6. In this wise a lighter stock may, if desired, be employed and a stronger structure will be produced by reason of the entire elimination of waste. As far as is known, it is believed that this is the first cone-shaped paper cup having a pointed apex to be formed from a continuous strip of paper without waste. In this connection it may be remarked that if desired the sharp tips or points 82, 84 shown in Figure 4 may be removed by cutting along the dotted lines 86, although it will be appreciated that such loss of paper is inconsequential and immaterial. In other words, notwithstanding the removal of these tiny segments it may be appropriately stated that the cup blank is formed without waste of material.

In forming the cup the apex 88 is located at the central point of the lower arcuate edge 18, although in accordance with old and well-known practice it may be located slightly within the edge of the blank if desired. The cup is rolled in the manner illustrated in Figure 4 and upon completion assumes the shape shown in Figures 5 and 6. The portion of the lower arcuate edge 18 located to the right of the axis AA of Figure 4 is folded within the cup and becomes the line illustrated by the reference numeral 90 of Figures 4, 5 and 6. The portion of the lower edge 28 located to the left of the axis AA folds around the outside of the cup and becomes the portion illustrated by the reference numeral 92 of Figures 5 and 6. The side edge 16-folds within the cup in the manner illustratedby the corresponding reference numeral in Figures 5 and 6 and the left side edge 14 folds on the outside as similarly illustrated in those figures. When the cup has been rolled inthe manner described it is symmetrically formed or wrapped with respect to its vertical axis BB of Figure 5. in the sense that the edges 14 and 16 are similarly positioned on opposite sides of the cup, the right and left portions 80, 82 are similarly positioned on opposite sides of a plane passing through the central axis BB and the point 2) which marks the junction of the tips 82 and 84 of the blank.

A cup formed in the manner described is strong and leak-proof. The practice heretofore in making paper cups has been to reinforce the apex portion by wrapping it thoroughly to form a multiple ply or wrap at that point. Also heretofore, as illustrated by the Curtin patent already referred to, it has been customary at the top portion of the cup to have only a very small overlap. This has resulted in weakness at the top of the cup and strength at the bottom. In accordance with the present invention it is believed that a cup should be strong at the top and that a double wrapped portion at the bottom is not necessary. It is in conformity with this view that the use of symmetric blanks is permitted and waste is eliminated. In the cup illustrated and described herein the apex or bottom has portions formed from a single thickness of paper, whereas the top or open end is double wrapped to afiord strength.

It is to be appreciated that the cup or container comprehended by this invention may be used for various purposes and that modifications in the design and construction of the cup may be made, for instance, other pliable sheet materials, e. g., moisture-proof regenerated cellulosic materials, rubberized sheet materials, and the like, may be substituted for paper without departing from the true spirit of the invention as set forth it the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In the art of forming conical receptacles, the step which comprises severing a continuous strip of sheet material from an edge thereof transversely of its longitudinal axis along successive arcs curving in the same direction and of the 1 at the straight line joining their centers at least a distance equal to the radii of curvature whereby successive blanks are formed having a convex side adapted to form the mouth of the receptacle and a concave side with the center of radius of curvature of the convex side not substantially outside of the blank, and successively forming conical vessels by rolling each blank around a point substantially at the center of radius of curvature of the convex side.

2. In the art of forming conical vessels. the steps which comprise transversely severing successive segments from the extremity of a continuous strip of paper from an edge thereof bymeans of a series of repeated and identical arcuate cuts curving in the same direction and with the centers of the radii of curvatures of said arcs on the same straight line joining their centers and with said successive arcuate lines spaced apart at the straight line joining their centers at least a distance equal to theradii of curvature whereby blanks are formed having a convex side adapted to form the mouth of the receptacle and a concave side with the center of radius of curvature of the convex side not substantially outside of the blank, and successively forming conical vessels by rolling each blank around a point substantially at the center of radius of curvature of the convex side.

3. In the art of forming conical vessels, the steps which comprise severing a continuous strip of paper at intervals along arcs of equal radii correspondingly curved and symmetrical with respect to the longitudinal center line of the strip a distance substantially equal to the radii of curvature whereby blanks are formed without waste having a convex side adapted to form the mouth of the receptacle and a concave side, and successively forming conical vessels by rolling each blank around a point substantially at the centerof radius of curvature of the convex side as the apex of the cone and with the convex side forming the periphery thereof.

4. In the art of forming conical vessels, the step which comprises severing a continuous strip of material transversely along successive single arcs capable of intersecting with each other and having equal radii with the centers of the radii of curvature on a straight line joining their centers and spaced apart at the straight line joining their centers. a distance substantially equal to the length of said radii .whereby blanks are formed having a convex side adapted to form the mouth of the receptacle and a concave side with the center of radius of curvature of the convex side substantially at the concave side and not outside of the blank, and'forming a conical vessel by rolling the blank around a point substansuccessive single arcs intersecting a straight side of said paper and having equal radii with the center of curvature of each arc on a straight line joining their centers and with said successive arcs spaced apart at the straight line joining their centers at least a distance equal to the radii of curvature whereby blanks are formedhaving a convex side adapted to form the mouth of the receptacle and a concave side with the center of radius of the curvature of the convex side not substantially outside of the blank, and forming a conical vessel by rolling the blank around a point substantially at the center of radius of curvature of the convex side as the apex of the cone.

6. In the art of forming conical vessels having a pointed apex, the steps which comprise severing a sheet material having substantially straight parallel sides along successive arcuate lines of substantially the same length and curvature with the centers of the radii of curvature on a straight line joining their centers and with said successive arcuate lines being spaced apart at the straight line joining the centers at least a distance equal to the radii of curvature, whereby blanks are 

